Tell us what you're seeing out there.
Clear morning for a tour which we became partly cloudy in the afternoon. We skied the SE ridge off Nadahini which has continuous slopes generally around 30°. There are a few spots the slope reaches about 32-34°. On the skin up we dug a snowpit just off the east side of the ridge. Snow depth as I recall was 310 cm. Our pit depth was a little over a meter. Three layers were relatively easy to identify at 35 cm, 50 cm, and maybe 70 cm down (did not measure the last one). Shear tests showed interfaces were all Q1. Two compression column tests resulted in 4 and 5 taps failing at the 35 cm depth. Slope here was 38°, which we measured after the tests; needless to say we got out of there right away after that. We continued up the ridge to the summit and decided to boot the rest of the approach as skinning on the rime ice was painstaking. On the hike back to our skis we remotely triggered a cornice that fell to the north, holy s***! This was terrifying and enlightening, I always thought we gave cornices the necessary respect by keeping our distance but we'll definitely be giving them a wider berth from here on. Back at the TH we could see that the cornice release triggered an avalanche. Curious, we toured up to the Nadahini Glacier the next day and took a few photos. The avalanche is estimated to be a size 3 with a maximum crown height of around maybe 1.5 meters, which also stepped down to deeper layers. The last photo shows a person standing at the toe of the avalanche for scale, snow/ice chunks were in size upwards of a snowmachine.
4/14/18 Natahini Glacier. Dug a pit at 5,000ft and N Aspect on 20 Degree slope. 290 cm total snow. 65 cm down January rain crust. Rounded facets below. 25 Cm of new snow on top of 1mm rain crust with faceting below. ECT no results. Boot one generated slight movement with very low energy. See video link: https://youtu.be/6Z5olEGWohQ Travel studies found corn below 4,000 ft. Above corn level some aspects had new snow more wind affected and slab/consolidated. If new snow feels like a slab in your travels, it is. Have caution in coming days on south aspects as solar radiation will likely consolidate this unsupported slab. What a winter.
Lutak Zone: 5,000ft W-N-E-S aspects. Rain snow combination on Tuesday with below freezing temps that night, left a supportive 2-3" ice crust at upper elevations, with an inch or two of fluff on top. Pockets of the surface slab were observed on a variety of aspects, usually at the apex below cliffs (see photo). Melt-freeze conditions, easy travel, fair confidence in the snowpack. Solar aspects had corn snow with thin faceted areas warming up. The clouds kept temps cool, and when the sun came out it was enough to trigger point releases.
Lutak Zone: 4,600ft S-E-N-W-aspects 24F, light N wind, sunny and clear. On S-E aspects above 2,000ft was hard re-frozen snow and above 4,000ft softer solar snow, with evidence of loose releases on un-supported slopes usually over rock. N-aspects had a mix of wind scoured snow and crust at ridge top then re-faceted surface snow lower down, the turning was good. W-aspect with late day sun were warming with increased ski pen. Overall confidence in the snowpack was high, no signs of observable instability.
Transitional Zone: 3,500ft E-aspect 24F light NW winds, high cloud cover. Not enough sunlight to warm up refrozen slopes. Variable crusts, soft pockets, and wind slab. Hard rain runnel crust from two weeks ago down 10-15cm with weak faceted interfacing below. Would need prolonged warm temperatures and strong solar radiation to re-activate the upper slab. Photo: Crown line mid-slope on NE facing couloir. Search out those layers, be vigilant between elevation bands, slopes, and aspects.